A microbolometer is an example of a type of infrared detector that may be used within an infrared imaging device (e.g., an infrared camera). For example, the microbolometer is typically fabricated on a monolithic silicon substrate to form an infrared (image) detector array, with each microbolometer of the infrared detector array functioning as a pixel to produce a two-dimensional image. The change in resistance of each microbolometer is translated into a time-multiplexed electrical signal by circuitry known as the read out integrated circuit (ROIC). The combination of the ROIC and the infrared detector array (e.g., microbolometer array) is commonly known as a focal plane array (FPA) or infrared FPA (IRFPA). Additional details regarding FPAs and microbolometers may be found, for example, in U.S. Pat. Nos. 5,756,999, 6,028,309, 6,812,465, and 7,034,301, which are herein incorporated by reference in their entirety.
Each microbolometer in the array is generally formed with two separate contacts, which may or may not be shared with adjacent microbolometers in the array. One contact is used to provide a reference voltage for the microbolometer while the other contact provides a signal path from the microbolometer to the ROIC. A drawback of a conventional contact is that it is too large and/or does not scale proportionally as semiconductor processing technologies transition to smaller dimensions. Consequently, as microbolometer dimensions are reduced, the conventional contact may consume a greater percentage of the area designated for the microbolometer, which reduces the area available for the desired resistive portion of the microbolometer and impacts microbolometer performance. As a result, there is a need for improved techniques for implementing contacts, such as for microbolometer-based focal plane arrays.